Process of making sulfur trioxid.



G. ESGHELLMANN & A. HARMUTH.

PROCESS OF MAKING SULFUR TRIOXID.

APPLICATION FILED MAY 7, 1907.

Patented Oct. 19, 1909.

Rae, rota rs w w w d W perature, carbon being precipitated UNITED sTATns PATENT are.

enone ESGHELLMANN AND ALBERT HARMUTH, or ST. PETERSB G, RUSSIA, AS-

SIGNORS TO GENERAL CHEMICAL COMPANY, OF NEW YORK, N.

0]! NEW YORK.

Y., a oortroaa'rron PROCESS OF MAKING SULFUR TEIOXID.

Patented Oct. 119, 11909.

Application filed May 7, 190i. Serial No. $752,390.

.To' all whom it may concern:

Be it known that we, GEoRo EsoEELI.- MANN and ALBERT HARMUTH, subjects of the King of Great Britain and the Emperor of Germany, respectively, residing at St. Petersburg, Russia, have invented certain new and useful Improvements in Processes of Making Sulfur Trioxid, of which the following isv a specification.

In the manufacture of sulfur trioxid bythe contact rocess, in which a mixture of sulfur dioxi and air is passed thro hone or more bodies of a cata ytic agent, or example finely divided platinu'mgit is of the greatest importance that the platinum be maintained in a pure and active condition. It has heretofore been recognized that the presence of arsenic, even in minute quantities, in the charge-mixture inljures the platinum' and greatly decreases t the process. r

In practice,'it is customary to force the mixture of sulfur dioxid, derived from the pyrites or sulfur burner, andair through the catalytic bodies by-means of a mechanical pump, either a reciprocating blowing-engine 'or a rotary blower. We have discovered that this pump is a heretofore unsuspected source of contamination of the charge-mixture by reason of the oil whichis employed for the lubrication of its moving parts. A small amount of the lubricating oil is taken up with the gases passing through the pump and carried with them into the contact chamber, where it is decomposed by the high temlatinum or other cata ytic a cut arbon, ike arsenic, greatly reduces t e efiiciency of the platinum and decreases the s eed and completeness of the synthetic reaction.

According to .the present invention, the gases leaving the pump are treated to remove *substantially every trace of oil before they enter the contact chamber, preferably by the use of a coke filter. 2 A suitable apparatus is shown in the ac companying drawing, in which the figure is ie eiiiciency of,v

ugon the a side elevation of a connected blowing-engine, filter and contact chamber, the latter shown in axial section.

The blowing engine A, here shown as of the ordinary vertical type with reciprocating piston, receives the mixture of sulfur dioxid and air through the pipe 1 and delivers it through the p1pe 2 tothe filter B. The filter is shown as a vertical cylindrical chamber,

the gases passing into a space in the lower end beneath the horizontal perforated plate 3 which supports the filter-bed 4. This bed preferably consists of pieces of coke, decreasing in size from the lower to the upper end of the bed. Such a filter-bed is found fur trioxidand escapes 'at-the top. A pipe 7 delivers the hot'mixture into the top of the upper chamber 8 of the contact apparatus. Thisuchamber has an upper per forated distributing plate 9 and a lower perforated plate 10 supporting a thin layer 11 of platinized asbestos. The lower chamber vl2 of the contact apparatus contains another body 13 of" platinized asbestos, supported on a perforated plate 14, and has a valved around a number of tubes carrying hot suloutlet pipe 15 for the products-of reaction.

A thermometer 16 is arranged to indicate the temperature in the catalytic layer 11, and the chambers are covered with heat insulation 17, The regulator 6 is arranged as a bypass from the pipe 15 and has a valved outlet 18. The valves in pipe 15 and this outlet ma be set. to shunt any desired portion of-tiie gaseous products through the regulator, in order to maintain a uniform tem erature in the catalytic body 11.

T e apparatus shown and described is lubricating oil from the gases in transit 10 No. 501,674, filed June 11, 1909; from the gas-pump to the contact-chamber.

We claim: In testimony whereof, we aflix our signal. In the contact process of making sulfur tures in presence of two witnesses.

claimed in our copending application, Ser.

5 .trioxid, the step which consists in remov-- GEORG ESCHELLMANN.

ing lubricating oil from the gases in transit ALBERT HARMUTH. from the gas-pump to the contact-chamber. Witnesses:

2. In the contact process of making sulfur H. A. LOVIA'GUINE,

trioxid, the step which consists in filtering 1 AUG. MIGHI's. 

